NOTE: These are the main Family Guy: Back to the Multiverse cheats that are usually applied by pressing down the right key combination. Please find the instructions on how to use these cheats below.

Cheat codes
At the start menu, select options, then cheat and enter one or more of these codes: *note that you will be unable to save upon activation. All credits goes to twisted0ne from the se7ensins.com forums.

NOTE: As their name suggests hints are not exactly Family Guy: Back to the Multiverse cheats, and are usually just simple (but very useful) tips on how you can unlock secret level, features, find hidden areas and such. Hopefully these will make playing Family Guy: Back to the Multiverse even more entertaining.

Steam Achievements
Bestest Infiltrator: Win an Infiltration map
Big Dipper: Earn all 21 stars in challenge mode
Bipolar: Switch between Brian and Stewie 10 times in Story mode
Bird Is The Word: Taunt 5 times in a row with Peter
Boom Headshot: Kill 75 enemies with headshots
Bunch of Chumps: Survive 15 waves of enemies in Multiverse Madness
Cartoon Apocalypse: Survive 30 waves in Multiverse Madness
Chicken Fight!: Complete the "Chicken Fight!" level
Chickens In Space: Complete the "Chickens In Space" level
Day Labor: Destroy all of the piñatas
Employee of the Month: Kill Vernon
First Kill: Successfully complete your first kill of a member of the opposing team in MultiplayerGrease Can't Save You Now: Win a Capture the "Greased-Up Deaf Guy" match
Handicapable: Complete the "Handicapable" level
Head Shot: Kill an enemy with a single shot to the head
Help From My Friends: Acquire any collectible special inventory items and use it 25 times in Story Mode
How Do I Jump?: Kill yourself with a grenade or satchel charge
IEDead: Kill 60 enemies with grenades/explosives
It's All Greek To Me: Complete the "It's All Greek To Me" level
Justified: Kill 500 enemies using Brian
Kings of Quahog: Win a deathmatch mode (free-for-all or as a team)
Little Dipper: Earn 10 stars in challenge mode
Lockdown: Shut out the other team from scoring in Capture the "Greased-Up Deaf Guy"
Long John Peter: Complete the "Long John Peter" level
Mort Will Now Lend You Credit: Buy everything available in the Store
Mr. Unpopular: Select Meg as a character for a Multiplayer match
Multi-kill: Perform a multi-kill with a melee weapon
Multi-kill with grenade: Perform a multi-kill with a grenade
No Cheese, Please: Complete the "No Cheese, Please" level
No Place Like Home: Complete the "No Place Like Home" level
Obsessed: Complete all secondary objectives
One Shot Kills: Successfully kill an enemy with one shot
Penny Pincher: Successfully collect $50,000
Pervert: Hang around Quagmire in a baby costume for 30 seconds
Pussy Whipped: Complete the "Pussy Whipped" level
Roadhouse: Kill 3 members of the opposing team with a melee attack before you die in Multiplayer
Santa's Sweatshop: Complete the "Santa's Sweatshop" level
Scorched Earth: Burn the Amish pot fields
Shut Up Meg: Kill Meg during a Multiplayer Match
Something's Amish: Complete the "Something's Amish" level
Stewie-nator: Kill 500 enemies using Stewie
Teabag a D-Bag: Taunt a dead opponent with Quagmire in Multiplayer
Teabaggin': Successfully perform a taunt 25 times
The Cleaner: Get a 10 kill streak in Deathmatch
There Is No Cake: Unlock all other Achievements found in the game
Ugly Tastes Terrible: Play poorly during the final showdown
We Be Clubbing: Defeat 10 enemies with a melee weapon
Wrecking Ball: Smash your opponent into something 20 times in the "Chicken Fight!" level